1. Field of the Invention
The present invention relates to a method of and device for removing and solidifying hydrocarbon oils and solvents from liquid. More specifically, the present invention relates to a filtration media used to selectively remove oil, solvent and other hydrocarbon compounds from liquid such that the liquid is discharged in a clean state. This method will result in the passive, inexpensive and foolproof filtration of stormwater and process liquid from spill containment areas, process areas, parking lots, and any other potential source of hydrocarbon containing liquid. In the event of a hydrocarbon spill or leak wherein an excess of hydrocarbons contacts the filtration media, the filtration media will form a plug to effectively contain the spill or leak.
2. Description of Related Art
In many commercial and industrial applications and installations, to prevent contamination of the environment by oils and solvents, spill containment systems are built that not only trap the potential spilled liquids but also any process liquid or rain/snow-melt liquid that comes in contact with the spill containment area. Federal, state and local regulations that mandate spill protection to minimize or eliminate hydrocarbon discharges to the environment are becoming more and more strict. The challenge is not just to prevent the spill, but to be able to handle the rainwater or process liquid that could be contaminated with hydrocarbons. With stormwater quality regulations being applied to parking lots and roofing systems, the difficulty is not just handling the hydrocarbons, but separating it efficiently and economically from a large quantity of stormwater.
Measures to separate oil and solvents from liquid are well known in the art. Passive means of separating oil and solvents from liquid typically use weirs of various heights to allow the oil and solvents which are lighter than liquid to be concentrated by collection or containment above the weirs. The liquid layer flows under the weirs in a somewhat cleaned state. These separators are far from 100% effective and are utilized only under very specific conditions. However, those conditions are not practicable with stormwater or spill containment area liquid discharges.
A popular mechanical means known in the art is moving a fabric belt through the liquid and oil mixture. As the fabric belt moves through the liquid and oil mixture, the fabric absorbs some of the oil. The belt is then squeezed through a device which removes the oil thereby separating the oil from the liquid. Such a device is rather crude, requires constant maintenance and power to operate, and it simply cannot remove all of the oil/solvent. Discharge of the liquid, even after cleaning by such a separator, would result in a significant amount of hydrocarbons being delivered into the environment.
Another mechanical device uses centrifugal force to separate the liquid from the lighter oils and solvents. As with the belt-type device described earlier, the centrifuge method requires a great deal of maintenance, a significant investment in equipment and it is simply not practical for the application of stormwater/spill containment area liquid discharge.
Chemical means known in the art for separating hydrocarbons from liquid employ specific absorbents or adsorbents. Adsorbents such as vermiculite, sand, oleophilic clays, tree bark and other similar materials merely hold the oil and solvents on their surface. However, in a passive filtration system, the liquid flow would pull a substantial amount of the oil and solvent off the surface of the solid adsorbent. Not only are these materials substantially ineffective, but in the event of a major hydrocarbon spill or leak, these materials allow the hydrocarbons to pass through to the environment.
Polymeric absorbents, mainly in booms and pillows, are also used to selectively absorb hydrocarbons from standing liquid and liquid systems. Typically, the granular absorbent materials solidify upon absorption of hydrocarbons. However, absorbents of this type are undesirable in a passive filtration system since the solidification of the absorbents would only absorb the bulk floating hydrocarbons while allowing sheen to be discharged.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a passive device for separating hydrocarbons from stormwater or spill containment areas capable of plugging and sealing off the containment area in the event of hydrocarbon overload as in a spill or leak.
It is another object of the present invention to provide a passive method for separating hydrocarbons from stormwater or spill containment areas capable of plugging and sealing off the containment area in the event of hydrocarbon overload as in a spill or leak.
It is yet another object of the present invention to provide a method of and device for filtering out hydrocarbons utilizing existing drainage and filtration resources capable of plugging and sealing off the containment area in the event of hydrocarbon overload as in a spill or leak.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The above and other objects and advantages, which will be apparent to one of skill in the art, are achieved in the present invention which is directed to, in a first aspect, a filtration media for removal of hydrocarbons from hydrocarbon containing liquid comprising: a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent. Upon contact with the hydrocarbon containing liquid, the hydrocarbons partially dissolve the polymeric absorbent prior to the filtration media substantially absorbing the hydrocarbons, while allowing hydrocarbon-free liquid to flow through the filtration media. The filtration media, upon contacting an excessive amount of hydrocarbons, forms a plug to seal and prevent further discharge of the hydrocarbons.
In another aspect, the present invention is directed to a hydrocarbon absorbing polymeric absorbent to prevent discharge of hydrocarbon containing liquid into an environment comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof, wherein upon contact with a hydrocarbon containing liquid, the polymeric absorbent forms a plug to seal off and prevent further discharge of the hydrocarbon containing liquid.
In a further aspect, the present invention is directed to a portable device for filtering hydrocarbons from hydrocarbon containing liquid comprising: a rigid container having a first end and a second end, the first end having an external lip and a first internal lip, and the second end having a second internal lip; a first porous layer disposed within the container on the second internal lip; and a filtration media comprising a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent, the filtration media compressed into the container. The device may be inserted into an existing drainage device such that a hydrocarbon containing liquid is filtered through the device allowing hydrocarbon-free liquid to flow from the device. Preferably, a gasket disposed under the external lip of the container provides a snug, temporary, leak proof seal when the container is inserted into an existing drainage device.
The hydrocarbon containing liquid flows through the container to contact the filtration media wherein the polymeric absorbent of the filtration media is adapted to form a tacky, semi-solid prior to absorption of the hydrocarbons creating a filtration barrier. Preferably, the filtration media has a thickness within the container adapted to substantially filter out hydrocarbons while capable of forming a plug in an excess of hydrocarbons.
Preferably, a float may be situated in a sufficient space within the container between the filtration media and the second internal lip wherein the float prevents back wash of any liquid through the container while allowing the hydrocarbon-free liquid to flow through.
In yet another aspect, the present invention is directed to a device for the containment of hydrocarbon containing liquid comprising: a rigid container having a first end and a second end, the first end having an external lip and a first internal lip, and the second end having a second internal lip; a first porous layer disposed within the container on the second internal lip; and a filtration media comprising a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent, the filtration media compressed into the container, wherein the device may be inserted into an existing drain such that upon contact with a hydrocarbon containing liquid having an excess of hydrocarbons, the filtration media forms a plug to seal and prevent further discharge of the hydrocarbon containing liquid. Preferably, a gasket is disposed under the external lip of the container to provide a snug, temporary, leak proof seal when the container is inserted into an existing drainage device.
In still yet another aspect, the present invention is directed to a method of filtering hydrocarbon containing liquid comprising the steps of: (a) providing a filtration media comprising a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent; (b) contacting the hydrocarbon containing liquid to the filtration media; and (c) removing hydrocarbons in the hydrocarbon containing liquid, wherein hydrocarbon-free liquid flows through the filtration media.
In yet another aspect, the present invention is directed to a method of preventing discharge of a hydrocarbon containing liquid containing an excessive amount of hydrocarbons comprising the steps of: (a) providing a filtration media comprising a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof, and an amount of filtration enabler; (b) contacting the hydrocarbon containing liquid to the filtration media; (c) forming a plug of the filtration media; and (d) preventing discharge of the hydrocarbon containing liquid.
In still a further aspect, the present invention is directed to a method of filtering out hydrocarbons in an existing drainage system comprising the steps of: (a) providing a porous layer fitted to an existing drainage opening; (b) filling the drainage opening with filtration media comprising a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent; (c) providing a second porous layer over the filtration media; (d) contacting hydrocarbon containing liquid to the filtration media; and (e) filtering the hydrocarbon containing liquid such that clarified liquid flowing through the filtration media is substantially hydrocarbon-free. Preferably, step (b) comprises filling the drainage opening with an amount of filtration media adapted to form a plug when contacted by an excessive amount of hydrocarbons and preventing discharge of the hydrocarbon containing liquid.
In a final aspect, the present invention is directed to a method of preventing discharge of a hydrocarbon containing liquid through an existing drainage system comprising the steps of: (a) providing a porous layer fitted to an existing drainage opening; (b) filling the drainage opening with filtration media comprising a polymeric absorbent comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent; (c) providing a second porous layer over the filtration media; (d) contacting the hydrocarbon containing liquid to the filtration media wherein the filtration media forms a plug; and (e) preventing discharge of the hydrocarbon containing liquid.
In all aspects of the present invention, the filtration enabler comprises recycled rubber, sand, gravel, vermiculite, recycled plastic chips, an inert, non-absorbent material, or a mixture thereof.